Here I will be grouping together all the key equations for Physics IGCSE
Topic 1 - Forces and Motion
average speed = distance travelled/ time taken v = s/t
acceleration = change in velocity/ time taken a = (v-u)/t
force = mass x acceleration F = ma
weight = mass x gravitational field strength w = mg
momentum = mass x velocity p = mv
moment = force x perpendicular distance from pivot moment = F x d
sum of anticlockwise moment = sum of clockwise moment
Topic 2 - Electricity
power = current x voltage p = I x V
energy = power x time E = p x t
energy = current x voltage x time E = I x V x t
charge = current x time Q = I x t
voltage = current x resistance V = I x R
Topic 3 - Waves
wave speed = frequency x wavelength v = f x λ
law of reflection: angle of incidence = angle of reflection
law of refraction: refractive index, n = sin i/sin r (sin i = sin angle of incidence, sin r = angle of refraction)
total internal reflection: refractive index, n = 1/sin c
Topic 4 - Energy
efficiency = useful energy output from system/ total energy output into system x 100
work = force x distance w = F x d
GPE = mass x gravitational field strenght x height GPE = m x g x h
KE = ½ mass x speed² KE = ½mv²
power = work done/ time taken P = W/t
Topic 5 - Solids, Liquid and Gases
density = mass/ volume p = m/v
pressure = force/ are p = F/A
pressure difference = height x density x gravity p = h x p x g (in liquids)
pressure is proportional to absolute temperature P1/T1 = P2/T2
Topic 6 - Magnetism
input voltage/ output voltage = primary turns/ secondary turns Vp/Vs = n1/n2
none in Topic 7 - Radioactivity